Autonomous driving technology relies heavily on navigation maps. For example, accuracy of navigation maps is critical to functions of autonomous driving vehicles, such as positioning, ambience recognition, decision making, and control. LiDAR systems have been widely used in autonomous driving and producing such maps. For example, LiDAR systems measure distance to a target by illuminating the target with laser light and measuring the reflected light with a sensor. Differences in laser return times and wavelengths can then be used to make digital three-dimensional (3D) representations of the target. The laser light used for LiDAR scan may be ultraviolet, visible, or near infrared. Because using a narrow laser beam as the incident light from the scanner can map physical features with high resolution, a LiDAR system is particularly suitable for applications such as sensing in autonomous driving and map surveys.
A typical LiDAR system normally includes a rotating (scanning) part that can be used for emitting laser beams and receiving the reflected light over a wide range of scanning angles, and a stationary part fixed to a vehicle and used for providing control signals and power to the rotating part and receiving sensing signals obtained by the rotating part. The more the laser beams the LiDAR system uses for scanning, the more thorough the LiDAR system can detect the surroundings. Typical LiDAR systems use a 32-beam LiDAR device for generating navigation maps to aid autonomous driving.
However, detection range and mapping accuracy of a single-LiDAR system may be limited by the physical characteristics of the LiDAR itself, such as the mounting position of the LiDAR system with respect to the vehicle and the field of view of the LiDAR device. As a result, the single-LiDAR system used with an autonomous driving vehicle may have blind spots in its detection range, and detection failure also occurs in some instances.
Embodiments of the disclosure address the above problems by providing systems and methods for LiDAR detection using multiple LiDAR devices.